U.S. patent number 9,814,232 [Application Number 15/026,855] was granted by the patent office on 2017-11-14 for insect control sheet.
This patent grant is currently assigned to NATIONAL UNIVERSITY CORPORATION KYOTO INSTITUTE OF TECHNOLOCY, NISSHA PRINTING CO., LTD.. The grantee listed for this patent is NATIONAL UNIVERSITY CORPORATION KYOTO INSTITUTE OF TECHNOLOGY, NISSHA PRINTING CO., LTD.. Invention is credited to Yoshihiro Harada, Tomoko Hirano, Yoshihide Inako, Hajime Mori, Tetsuya Nakayama, Yasuisa Takinishi.
United States Patent |
9,814,232 |
Nakayama , et al. |
November 14, 2017 |
Insect control sheet
Abstract
An insect control sheet containing a Cry polyhedron prepared by
fixing an insecticidal protein (a Cry toxin) produced by Bacillus
thuringiensis to a polyhedron of polyhedrin protein is provided.
The insect control sheet contains the Cry polyhedron and is used by
floating on water. The insect control sheet is floatable on water,
and includes a pure matrix layer 20 and a toxin-containing matrix
layer 30 containing the Cry polyhedron 51 which are layered on the
underside of a sheet-shaped first sheet substrate 10. The pure
matrix layer 20 is composed of a degradable or water-soluble second
material and the toxin-containing matrix layer 30 is composed of a
degradable or water-soluble third material and the Cry polyhedron.
The toxin-containing matrix layer sustainably releases the Cry
polyhedron to the water on which the insect control sheet is
floated.
Inventors: |
Nakayama; Tetsuya (Kyoto,
JP), Takinishi; Yasuisa (Kyoto, JP), Inako;
Yoshihide (Kyoto, JP), Mori; Hajime (Kyoto,
JP), Hirano; Tomoko (Kyoto, JP), Harada;
Yoshihiro (Kyoto, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
NISSHA PRINTING CO., LTD.
NATIONAL UNIVERSITY CORPORATION KYOTO INSTITUTE OF
TECHNOLOGY |
Kyoto-shi, Kyoto
Kyoto-shi, Kyoto |
N/A
N/A |
JP
JP |
|
|
Assignee: |
NISSHA PRINTING CO., LTD.
(Kyoto-shi, Kyoto, JP)
NATIONAL UNIVERSITY CORPORATION KYOTO INSTITUTE OF
TECHNOLOCY (Kyoto-shi, Kyoto, JP)
|
Family
ID: |
53878189 |
Appl.
No.: |
15/026,855 |
Filed: |
February 12, 2015 |
PCT
Filed: |
February 12, 2015 |
PCT No.: |
PCT/JP2015/053784 |
371(c)(1),(2),(4) Date: |
April 01, 2016 |
PCT
Pub. No.: |
WO2015/125684 |
PCT
Pub. Date: |
August 27, 2015 |
Prior Publication Data
|
|
|
|
Document
Identifier |
Publication Date |
|
US 20160249609 A1 |
Sep 1, 2016 |
|
Foreign Application Priority Data
|
|
|
|
|
Feb 18, 2014 [JP] |
|
|
2014-028592 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A01M
1/2016 (20130101); A01M 1/2055 (20130101); A01N
25/34 (20130101); A01N 63/50 (20200101); A01N
63/50 (20200101); A01N 63/23 (20200101); A01N
63/50 (20200101); A01N 25/10 (20130101); A01N
25/34 (20130101) |
Current International
Class: |
A01N
25/34 (20060101); A01M 1/20 (20060101); A01N
63/02 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
PCT/IB/326, "Notification Concerning Transmittal of International
Preliminary Report on Patentability for International Application
No. PCT/JP2015/053784," dated Sep. 1, 2016. cited by applicant
.
PCT/IB/373, "International Preliminary Report on Patentability for
International Application No. PCT/JP2015/053784," dated Aug. 23,
2016. cited by applicant .
PCT/ISA/237, "Written Opinion of the International Searching
Authority for International Application No. PCT/JP2015/053784,"
dated May 19, 2015. cited by applicant .
PCT/IB/338, "Notification of Transmittal of Translation of the
International Preliminary Report on Patentability for International
Application No. PCT/JP2015/053784," dated Sep. 1, 2016. cited by
applicant .
PCT, "International Search Report for International Application No.
PCT/JP2015/125684". cited by applicant .
Shinichiro Asano "Possibility of insect pathogenic microbe as
hygine insect pest control materials", Journal of Pesticide
Science. cited by applicant .
Michio Himeno "Improvement and mechanism of action of microbial
pesticides", Microbes and Environments, 1999, vol. 14, No. 4,, 245
to 252. cited by applicant .
Biomaterials 30 (2009) 4297-4308, Structure-based targeting of
bioactive proteins into cypovirus polyhedra and appliaiton to
immobilized cytokines for mammalian cell culture, Hiroshi Ijiri et
al. cited by applicant .
Using the bio-insecticide Bacillus thuringiensis israelensis in
Mosquito control, www.intechopen.com. cited by applicant .
Binding of Cyt1Aa and Cry11Aa Toxins of Bacillus thuringiensis
Serover israelensis to Brush Border Membrane Vesicles of Tipula
paludosa (Diptera: nematocera.sub.--and Subsequent pore formation,
Journals.ASM.org. January 29, 20114. cited by applicant .
Yoshihiro Harada, Eiji Kotani; Shinichiro Asano & Hajime Mori;
"Fixation of the .delta.-endotoxins of Bacillus thuringiensis to
polyhedra and application thereof", A6 in "The collection of the
lectures in Kansai area", distributed at "The Academic Lectures for
the Study and Use of Insect Functions", The Joint Meeting of the
Japanese Society of Sericultural Science, Nov. 10, 2012. cited by
applicant.
|
Primary Examiner: Alker; Kathleen I
Attorney, Agent or Firm: Kanesaka; Manabu
Claims
The invention claimed is:
1. An insect control sheet for floating on water, comprising: a
sheet-shaped first sheet substrate comprising a degradable first
material, a pure matrix layer layered on an underside of the first
sheet substrate; a toxin-containing matrix layer layered on an
underside of the pure matrix layer; a floating member for floating
the insect control sheet on water contained in one of the first
substrate, the pure matrix layer and the toxin-containing matrix
layer, wherein the pure matrix layer comprises a degradable or
water-soluble second material, the toxin-containing matrix layer
comprises a degradable or water-soluble third material and Cry
polyhedron that is an insecticidal protein produced by Bacillus
thuringiensis fixed to a polyhedron of polyhedrin protein, the
toxin-containing matrix layer is adapted to release the Cry
polyhedron by decomposition or dissolution of the third material,
to the water on which the insect control sheet floats, and the
toxin-containing matrix layer and the pure matrix layer degrade or
dissolve in water in a shorter time than that required for the
decomposition or dissolution of the first sheet substrate.
2. The insect control sheet according to claim 1, wherein the
second material is composed of same ingredients as that of the
third material.
3. The insect control sheet according to claim 1, wherein the third
material comprises at least one ingredient selected from the group
consisting of collagen, gelatin, chitin, chitosan,
glycosaminoglycan, hyaluronic acid, chondroitin sulfate, elastin,
fibronectin, laminin, fibrin, alginic acid, fibroin, starch,
pectin, pectic acid, agarose, heparin, carboxymethyl cellulose,
cellouronic acid, polyvinyl alcohol, polyethylene glycol, methyl
polymethacrylate, methacrylate ester polymers, silicone resins,
polylactic acid, polyglycolic acid, poly.epsilon.-caprolactone,
bovine serum albumin, casein, sucrose, and mixtures, polymers,
copolymers and cross-linked products thereof.
4. The insect control sheet according to claim 1, wherein the first
sheet substrate comprises nonwoven fabric or mesh sheet.
5. The insect control sheet according to claim 1, wherein the
floating member comprises bubbles contained in the first sheet
substrate.
6. The insect control sheet according to claim 1, further
comprising a sheet-shaped second sheet substrate that is layered on
a top side of the first sheet substrate, wherein the floating
member comprises bubbles contained in the second sheet
substrate.
7. The insect control sheet according to claim 1, wherein the
floating member comprises bubbles contained in the toxin-containing
matrix layer.
8. The insect control sheet according to claim 1, wherein the first
sheet substrate comprises two layers, and the floating member
comprises an air cell being formed between the two layers of the
first sheet substrate.
9. The insect control sheet according to claim 1, wherein the
floating member comprises a patterned hydrophobic region being
formed on the underside of the first sheet substrate, and the pure
matrix layer and toxin-containing matrix layer are layered on a
part of the underside of the first sheet substrate where the
hydrophobic region is not formed.
10. The insect control sheet according to claim 1, wherein the
floating member comprises a hydrophobic region being formed on a
top side of the first sheet substrate.
11. The insect control sheet according to claim 1, wherein a design
is made on the underside of the first sheet substrate.
Description
RELATED APPLICATIONS
The present application is National Phase of International
Application No. PCT/JP2015/053784 filed Feb. 12, 2015, and claims
priority from Japanese Application No. 2014-028592, filed Feb. 18,
2014, the disclosure of which is hereby incorporated by reference
herein in its entirety.
TECHNICAL FIELD
The present invention relates to an insect control sheet used by
floating on water.
BACKGROUND ART
The insecticidal protein produced by Bacillus thuringiensis
(hereinafter referred to as a "Cry toxin") exerts an insecticidal
activity against certain species of insects. The Cry toxin produced
by Bacillus thuringiensis serovar israelensis is known to be toxic
to mosquito larvae.
The inventors fixed the Cry toxin to a polyhedron of polyhedrin
protein, which is a protein microcrystal produced by Bombyxmori
cypovirus (BmCPV). The Cry toxin fixed to the polyhedron is
hereinafter referred to as a "Cry polyhedron". A tag for fixing the
Cry toxin to the polyhedron of polyhedrin protein was added to the
N-terminal of the Cry toxin. Then the tagged Cry toxin was fixed to
the polyhedron of polyhedrin protein.
The inventors reported that
(1) the Cry polyhedron exerted an insecticidal activity against
mosquito larvae, and
(2) mosquito larvae which ingested the Cry polyhedron died (refer
to the non-patent literature 1).
On the other hand, a method for making mosquito larvae easily
ingest the Cry polyhedron at their habitat in natural environment
was not found at that time.
CITATION LIST
Non-Patent Literature
NPL 1: HARADA Yoshihiro, KOTANI Eiji, ASANO Shin-ichiro, & MORI
Hajime, "Fixation of the .delta.-endotoxins of Bacillus
thuringiensis to polyhedra and application thereof", A6 in "The
collection of the lectures in Kansai area", distributed at "the
Academic Lectures for the Study and Use of Insect Functions", the
Joint Meeting of the Japanese Society of Sericultural Science, Nov.
10, 2012
SUMMARY OF INVENTION
Technical Problem
The problems to be solved by the invention is fabricating insect
control sheets and articles containing the Cry polyhedron as the
active ingredient, and harmful insects easily ingesting the Cry
polyhedron, and also finding a means of the same.
Other problems to be solved by the present invention are apparently
explained in the following description of the present
invention.
Solution to Problem
The means for solving the problems will be described below. The
signs used in the description correspond to the signs in the
embodiments of the present invention for the convenience of
understanding, and the present invention is not restricted within
the scope of the embodiments. The numbers used as the signs may
collectively represent the parts, and alphabetical letters are
sometimes added to the numbers to represent each of the parts in
the working examples mentioned below.
An insect control sheet according to an embodiment of the present
invention comprises an insecticidal protein produced by Bacillus
thuringiensis (hereinafter referred to as a "Cry toxin") and fixed
to a polyhedron of polyhedrin protein (the Cry toxin fixed to the
polyhedron hereinafter referred to as a "Cry polyhedron"), and is
used by floating on water surface. The insect control sheet
comprises a sheet-shaped first sheet substrate (10), a pure matrix
layer (20) layered on the underside of the first sheet substrate
(10), and a toxin-containing matrix layer (30) containing the Cry
polyhedron (51) and layered on the underside of the pure matrix
layer, and the insect control sheet floats on water. Also, the
insect control sheet comprises,
the pure matrix layer is composed of a degradable or water-soluble
second material,
the toxin-containing matrix layer is composed of a degradable or
water-soluble third material and the Cry polyhedron; and
the toxin-containing matrix layer sustainably releases the Cry
polyhedron to the water on which the insect control sheet is
floated.
Harmful insects include those killed by the Cry toxin, for example,
insects falling into Diptera, Coleoptera and Lepidoptera.
Mosquito larvae (called "bofura" or "bofuri" in Japanese) falling
into the category of harmful insects usually float in water between
water surface and several centimeters below water surface. Mosquito
larvae regularly go up to water surface to breathe and feed in
water. The Cry polyhedron has a specific gravity of 1.27.
A suspension of the Cry polyhedron may come to one's mind as a Cry
polyhedron-containing insecticide to kill mosquito larvae. However,
the Cry polyhedron soon settles out after addition of the
suspension to water without remaining within several centimeters
below water surface, and fails to provide mosquito larvae the
chance of ingestion. Thus the suspension of the Cry polyhedron
cannot effectively exert its insecticidal activity against mosquito
larvae.
The insect control sheet of the present invention (1) floats on
water surface, and (2) comprises, in addition to other elements,
the toxin-containing matrix layer composed of the degradable or
water-soluble third material and the Cry polyhedron. The
toxin-containing matrix layer sustainably releases the Cry
polyhedron to the water on which the insect control sheet is
floated. Consequently the Cry polyhedron is constantly supplied to
the habitat, namely feeding place, of mosquito larvae, and exerts
its insecticidal activity against mosquito larvae which ingest the
Cry polyhedron.
The insect control sheet according to a preferred embodiment of the
present invention may include the second material composed of the
same ingredients as that of the third material. The third material
may be composed of specific ingredients.
The specific ingredients have low human health risks to make the
insect control sheet preferable to be used in a water tank for
daily life water including drinking water.
Another insect control sheet according to a preferred embodiment of
the present invention includes the first sheet substrate composed
of a degradable first material. The toxin-containing matrix layer
and the pure matrix layer may degrade or dissolve in water in a
shorter time than that required for the decomposition or
dissolution of the first sheet substrate.
The insect control sheet of the preferred embodiment is composed of
the elements all of which degrade or dissolve in water. The sheet
substrate retains its form throughout the period in which the
toxin-containing matrix layer releases the Cry polyhedron, and thus
enables the sustainable release of the Cry polyhedron from the
degradable insect control sheet.
The insect control sheet of the preferred embodiment has the
advantage that the sheet leaves no residue after use.
An insect control sheet according to another preferred embodiment
of the present invention may include the first sheet substrate
composed of nonwoven fabric or mesh sheet. The first sheet
substrate composed of nonwoven fabric or mesh sheet has the
advantage that such material increases the amount of the Cry
polyhedron retained per unit area of the first sheet substrate. In
addition, the porous structure of nonwoven fabric or mesh sheet
enables easy manufacture of a floatable body by filling the first
sheet substrate with bubbles.
The first sheet substrate may be a flat plate including plates,
thin plates, sheets and films. One side or both sides of the flat
plate may be smooth, or may be wholly or partially rough.
An insect control sheet according to another preferred embodiment
of the present invention has a floating member for floating the
insect control sheet on water which is bubbles or air cells
contained in one of members comprising the insect control
sheet.
In other words, the insect control sheet may include the first
sheet substrate containing bubbles, a sheet-shaped second sheet
substrate containing bubbles and layered on the top side of the
first sheet substrate, and the toxin-containing matrix layer
containing bubbles. In addition the first sheet substrate may be
composed of two layers between which air cell is formed.
An insect control sheet according to yet another preferred
embodiment of the present invention has a floating member for
floating the insect control sheet on water which is a hydrophobic
region formed on the surface of the insect control sheet.
In other words, the insect control sheet may include a patterned
hydrophobic region formed on the underside of the first sheet
substrate and the pure matrix layer and the toxin-containing matrix
layer layered on the part of the underside of the first sheet
substrate where the hydrophobic region is not formed. The insect
control sheet may also include the hydrophobic region formed on the
top side of the first sheet substrate.
Another insect control sheet according to a preferred embodiment of
the present invention may include a design made on the underside of
the first sheet substrate.
The design is made by printing or drawing, and the examples of the
design are letters and graphics. The design may represent, for
example, a sign indicating the time for the replacement of the
insect control sheet or a caution for proper hygiene
For example, the hydrophobic part patterned on the underside of the
first sheet substrate mentioned above may be formed into a design
including letters and graphics. The hydrophobic part may also be
formed into a part of such letters and graphics. In addition, the
design on the underside of the first sheet substrate may be covered
with the pure matrix layer and the toxin-containing matrix layer to
be hidden before the insect control sheet is used, and may appear
after the use of the insect control sheet for a certain period as
the result of the disappearance caused by the decomposition or the
dissolution of the toxin-containing matrix layer and the pure
matrix layer.
The method of exposing the design after the use of the insect
control sheet for a certain period may include the use of the
second and third materials colored with dyes. Edible dyes are
preferable for coloring the insect control sheet used in a water
tank of daily life water including drinking water.
An insect control article being used by floating on water according
to another embodiment of the present invention comprises a body
floatable on water,
a pure matrix layer layered on the underside of the body, and
a toxin-containing matrix layer layered on the underside of the
pure matrix layer.
The insect control article also comprises:
the pure matrix layer comprises a degradable or water-soluble
second material;
the toxin-containing matrix layer comprises a degradable or
water-soluble third material and the Cry polyhedron; and
the toxin-containing matrix layer sustainably releases the Cry
polyhedron to the water on which the insect control article is
floated.
A transfer sheet according to another embodiment of the present
invention is used to fabricate the insect control sheet or insect
control article. The transfer sheet comprises the toxin-containing
matrix layer containing the Cry polyhedron, the pure matrix layer,
and an adhesive layer layered in the order on one surface of a
transfer-sheet substrate. Also, the transfer sheet comprises;
the toxin-containing matrix layer comprising a degradable or
water-soluble third material and the Cry polyhedron; and
the pure matrix layer comprising a degradable or water-soluble
second material.
The present invention, preferred embodiments of the present
invention and the elements contained therein can be combined as far
as possible to work the invention.
Advantageous Effects of Invention
The insect control sheet according to one embodiment of the present
invention includes the toxin-containing matrix layer composed of
the degradable or water-soluble third material and the Cry
polyhedron and the pure matrix layer sandwiched between the first
sheet substrate and the toxin-containing matrix layer, in addition
to other elements.
Owing to the structure, the Cry polyhedron is gradually released
into water connected with the degradation or dissolution of the
toxin-containing matrix layer. In addition, the pure matrix layer
prevents the Cry polyhedron from contacting with the first sheet
substrate so as to facilitate release of the Cry polyhedron.
The insect control article according to another embodiment of the
present invention includes the toxin-containing matrix layer
composed of the degradable or water-soluble third material and the
Cry polyhedron, and the pure matrix layer sandwiched between the
underside of the body and the toxin-containing matrix layer, in
addition to other elements.
Owing to the structure, the Cry polyhedron is gradually released
into water connected with the degradation or dissolution of the
toxin-containing matrix layer. In addition, the pure matrix sheet
prevents the Cry polyhedron from contacting with the first sheet
substrate so as to facilitate release of the Cry polyhedron.
The transfer sheet according to another embodiment of the present
invention includes, in addition to other elements, the
toxin-containing matrix layer containing the Cry polyhedron, the
pure matrix layer, and the adhesive layer layered in this order on
one surface of the transfer-sheet substrate. Thus the transfer
sheet can be used to transfer the layers from the transfer-sheet
substrate to the first sheet substrate or the body of any forms and
properties, and advantageously used to fabricate an insect control
sheet or article having the layers of properly controlled thickness
and uniformity.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a sectional view illustrating the first insect control
sheet 1a.
FIG. 2 is a sectional view illustrating the second insect control
sheet 1b.
FIG. 3 is a sectional view illustrating the third insect control
sheet 1c.
FIG. 4 is a sectional view illustrating the fourth insect control
sheet 1d.
FIG. 5 is a sectional view illustrating the fifth insect control
sheet 1e.
FIG. 6 is a sectional view illustrating the sixth insect control
sheet 1f.
FIG. 7 is a sectional view illustrating the seventh insect control
sheet 1g.
FIG. 8 is a sectional view illustrating the insect control
article.
FIG. 9 is a sectional view illustrating the transfer sheet for
fabricating the insect control article.
FIG. 10 is a sectional view illustrating the eighth insect control
sheet 1h.
FIG. 11 is a sectional view illustrating the ninth insect control
sheet 1i.
DESCRIPTION OF EMBODIMENT
The insect control sheet, insect control article, and transfer
sheet according to the embodiments of the present invention are
further described below referring to the figures. Some of the
figures referred herein are schematic diagrams containing
magnification of some elements for easy understanding of the
present invention. Thus some of the dimensions or dimensional ratio
between the elements may be different from that of the actual
sheets and articles.
In the sectional views showing the layer structure, the blank
between the layers is made for the convenience of explanation of
the layer structure. In the actual insect control sheets or insect
control articles, the layers are attached to each other.
The dimensions, materials, forms, and relative positions of the
members and parts described in the working examples of the present
invention merely explain the present invention and are not intended
to restrict the scope of the present invention unless otherwise
specified.
FIG. 1 is a sectional view illustrating the first insect control
sheet 1a.
The first insect control sheet 1a includes the pure matrix layer 20
layered on the underside of the first sheet substrate 10 and the
toxin-containing matrix layer 30 layered on the underside of the
pure matrix layer 20.
In the present invention and in this specification, the top side
and underside are defined for the explanation. When the insect
control sheet is placed on water, the side contacting with water or
sinking into water is defined as the underside while the side
facing the atmosphere is defined as the top side. This applies to
the insect control sheets from the second to ninth and the insect
control article explained below.
The first sheet substrate 10 is a support member for the pure
matrix layer 20 and the toxin-containing matrix layer 30. The first
sheet substrate 10 is composed of the first material. The first
material may be degradable, water-soluble, persistent, or poorly
water soluble. The first material should preferably be degradable
or water-soluble in terms of the protection of natural environment.
The first material should preferably have low human health risks,
because the insect control sheet may be used to control harmful
insects in a water tank reserving daily life water.
The first sheet substrate has a sheet shape extending
two-dimensionally. The sheet shape extending two-dimensionally
includes, for example, sheet, film and paper. The thickness of the
first sheet substrate is not specifically restricted, and
preferably ranges from 16 .mu.m (micrometers) to 3 mm
(millimeters). A thickness within the range gives sufficient
strength to the first sheet substrate and enables the pure matrix
layer 20 and the toxin-containing matrix layer 30 to be readily
layered. In addition, the first sheet substrate having such
thickness facilitates designing of the time required for the
decomposition of degradable materials in natural environment.
The two-dimensional size of the first sheet substrate is not
specifically restricted, and may be determined according to the
area of water surface in a water tank to which the insect control
sheet is placed.
The pure matrix layer 20 separates the toxin-containing matrix
layer 30 and the first sheet substrate 10. If the Cry polyhedron
contained in the toxin-containing matrix layer contacted with the
first sheet substrate, the Cry polyhedron would adhere to the first
sheet substrate and would not be easily released from the first
insect control sheet.
For solving the trouble mentioned above, the insect control sheet
includes the pure matrix layer 20 which separates the
toxin-containing matrix layer 30 and the first sheet substrate 10
to secure the release of the Cry polyhedron.
The pure matrix layer 20 is composed of the degradable or
water-soluble second material. The second material should
preferably have low human health risks, because the insect control
sheet may be used to control harmful insects in a water tank
reserving daily life water. The thickness of the pure matrix layer
is not specifically restricted, and can be optionally determined,
preferably within the range from 5 nm (nanometers) to 50 .mu.m
(micrometers). A thickness within the range enables the separation
of the toxin-containing matrix layer 30 and the first sheet
substrate 10.
The pure matrix layer 20 can be formed by coating, printing or
dipping.
The term "pure" of the pure matrix layer 20 means that the layer is
free of toxins. With this concept, the matrix layer containing
toxins is called "the toxin-containing matrix layer 30". The
material constituting the pure matrix layer 20 does not mean "a
pure material purified by removing impurities to the utmost
limit".
The toxin-containing matrix layer 30 is composed of the degradable
or water-soluble third material and the Cry polyhedron. The
toxin-containing matrix layer 30 releases the Cry polyhedron caused
by the decomposition or dissolution of the third material.
The toxin-containing matrix layer 30 is composed of the degradable
or water-soluble third material. The third material should
preferably have low human health risks, because the insect control
sheet may be used to control harmful insects in a water tank
reserving daily life water. The thickness of the toxin-containing
matrix layer 30 is not specifically restricted, and may be
optionally determined preferably within the range from 5 nm
(nanometers) to 1 mm (millimeter). A thickness within the range
enables the release of the Cry polyhedron. The lower limit of the
thickness, 5 nm (nanometers), is the thickness of the part of the
toxin-containing matrix layer where only the third material
constitutes the matrix layer (the part where the Cry polyhedron is
not contained).
The Cry polyhedron is produced by fixing the Cry toxin to a
polyhedron of polyhedrin protein, which is a protein microcrystal
produced by Bombyxmori cypovirus (BmCPV). A tag for fixing the Cry
toxin to the polyhedron of polyhedrin protein is added to the
N-terminal of the Cry toxin. Then the tagged Cry toxin is fixed to
the polyhedron of polyhedrin protein. In the method, the Cry toxin
can be fixed to the polyhedron by adding the N-terminal
.alpha.-helix H1 (refer to Reference C-1) of the polyhedrin protein
to the N terminal of the Cry toxin. The polyhedron, which
solubilizes at a pH of 10 or more, functions as a carrier suitable
for the Cry toxin, because the polyhedron solubilizes under the
alkaline condition in the digestive tract of mosquito larvae (refer
to Reference C-2). The diameter of the circumscribed sphere of the
Cry polyhedron, which represents the size of the Cry polyhedron,
ranges from 3 .mu.m (micrometers) to 15 .mu.m (micrometers).
The Cry toxin fixed to the Cry polyhedron and contained in the
toxin-containing matrix layer is an insecticidal protein usually
produced by bacteria included in Bacillus thuringiensis and its
varieties or subspecies. Preferable Cry toxins are Cry11Aa, Cry4Aa,
Cry4Ba, and Cry10Aa produced by Bacillus thuringiensis serovar
israelensis, and Cry11Aa is more preferable.
Cry11Aa is highly toxic to the larvae of Aedes which transmit
arbovirus including dengue virus, Culex which transmit filaria, and
Anopheles which transmit plasmodium (refer to Reference C-3).
Reference
Reference C-1: Hiroshi Ijiri, Fasseli Coulibaly, Gento Nishimura et
al., Structure-based targeting of bioactive proteins into cypovirus
polyhedra and application to immobilized cytokines for mammalian
cell culture, Biomaterials 30 (2009) 4297-4308
Reference C-2: Despres Laurence, Lagneau Christophe & Frutos
Roger, Using the Bio-Insecticide Bacillus thuringiensis israelensis
in Mosquito Control, Pesticides in the Modern World--Pests Control
and Pesticides Exposure and Toxicity Assessment, Edited by Dr.
Margarita Stoytcheva, Publisher In tech, September, 2011
Reference C-3: Jesko Oestergaad, Ralf-Udo Ehlers, Amparo C.
Martinerz-Ramirez et al., Binding of Cyt1Aa and Cry11Aa Toxins of
Bacillus thuringiensis Serovar israelensis to Brush Border Membrane
Vesicles of Tipula paludosa (Diptera: Nematocera) and Subsequent
Pore Formation, Applied and Environmental Microbiology, Vol. 73,
No. 11, (June 2007) 3623-3629
The toxin-containing matrix layer 30 can be formed by coating or
printing with a mixture prepared by mixing the third material and
the Cry polyhedron.
The first insect control sheet 1a floats on water, and sustainably
releases the Cry polyhedron into the habitat of mosquito larvae
between water surface and several centimeters below water surface
to make mosquito larvae ingest the Cry polyhedron.
The Cry polyhedron is sustainably released into water from the
toxin-containing matrix layer 30 when the first insect-control
sheet 1a is placed on water surface.
The first material is a constituent of the first sheet substrate
10. Examples of the degradable or water-soluble first material
include starches and starch mixtures with polylactic acid, chitin,
chitosan, polyhydroxyalkanoates, polybutylene succinate, cellulose
and protein; and natural fibers (cotton, wool, hemp, pulp, silk,
kenaf, banana fiber and bamboo fiber) and their blends. These
examples have low human health risks.
Examples of the persistent first material include resin sheets of
polypropylene resins, polyethylene resins, polyamide resins,
polyester resins, acrylic resins, polyvinyl chloride resins,
polycarbonate resins, polyurethane resins, polystyrene resins, and
acetate resins; cellulose sheets, such as glassine paper, coated
paper, and cellophane; and composites of those materials.
The third material is a matrix material constituting the
toxin-containing matrix layer 30. Examples of the third material
include collagen, gelatin, chitin, chitosan, glycosaminoglycan,
hyaluronic acid, chondroitin sulfate, elastin, fibronectin,
laminin, fibrin, alginic acid, fibroin, starch, pectin, pectic
acid, agarose, heparin, carboxymethyl cellulose, cellouronic acid,
polyvinyl alcohol, polyethylene glycol, methyl polymethacrylate,
methacrylate ester polymers, silicone resins, polylactic acid,
polyglycolic acid, poly.epsilon.-caprolactone, bovine serum
albumin, casein, sucrose, and the mixtures, polymers, copolymers
and cross-linked products of those substances. These examples have
low human health risks.
The second material is a constituent of the pure matrix layer 20.
Examples of the second material are the same as that mentioned in
the description of the third material.
The second and third materials for the first insect control sheet
1a should preferably consist of the same ingredients, because the
degradation time of the toxin-containing matrix layer 30 and the
pure matrix layer 20 can be easily designed in designing the first
insect control sheet 1a. In addition, the first insect control
sheet 1a can be produced with a smaller number of materials and in
a simpler process which enable easier process control.
The sheet substrate 10 of the first insect control sheet 1a should
preferably be composed of the degradable first material, and the
second and third materials should preferably degrade or dissolve in
water faster than the first material, because the second and third
materials having such properties ensure that all of the Cry
polyhedron contained in the toxin-containing matrix layer 30 will
be gradually released.
The time required for the toxin-containing matrix layer 30 to
degrade or dissolve in water should range usually from 15 days to
90 days, preferably from 15 days to 60 days, and more preferably
from 25 days to 45 days.
The time required for the pure matrix layer 20 to degrade or
dissolve in water should range usually from the time 5 days shorter
to the time 10 days longer than the time required for the
degradation or dissolution of the toxin-containing matrix layer,
preferably from the time 3 days shorter to the time 10 days longer,
and more preferably from the time 1 day shorter to the time 1 day
longer. The time required for the degradation or dissolution of the
layers, however, cannot usually be designed by the day (24 hours),
because the advancement of the degradation or dissolution of the
layers is influenced by water temperature and quality which vary
greatly. The degradation time is therefore forced to be set up
roughly on a monthly basis. It is preferable to design the time
required for the degradation or dissolution of the two layers by
employing the same material for the second and third materials to
synchronize their degradation and controlling the thickness of the
layers and concentration of the materials in the layers.
The degradable or water-soluble first sheet substrate usually
degrades or dissolves in water in 180 days and should preferably
degrade or dissolves in the time from 30 days to 60 days longer
than the time required for the toxin-containing matrix layer to
degrade or dissolve in water.
The first sheet substrate may be composed of nonwoven fabric or
mesh sheet.
The eighth insect control sheet 1h schematically drawn in FIG. 10
is composed of the first sheet substrate 10 of nonwoven fabric. The
surface of the nonwoven fabric is designed to form convexes and
concaves which are larger than the Cry polyhedron 51. Thus the
insect control sheet composed of the first sheet substrate of
nonwoven fabric retains greater amount of the Cry polyhedron per
unit area than the insect control sheet composed of the first sheet
substrate of a flat plate. In addition, the porous structure of
nonwoven fabric facilitates the manufacture of floatable object
where the first sheet substrate is aerated.
The diagram of the eighth insect control sheet 1h in FIG. 10 shows
the first sheet substrate 10, the pure matrix layer 20, and the
toxin-containing matrix layer 30 being attached to each other
without having a space between them.
The first material constituting the nonwoven fabric of the first
sheet substrate 10 may be selected from various materials without
any restriction. Natural fibers (cotton, wool, hemp, pulp, silk,
kenaf, banana fiber, and bamboo fiber, etc.) are preferable for the
first material because of their low human health risks.
The ninth insect control sheet 1i schematically drawn in FIG. 11 is
composed of the first sheet substrate 10 of mesh sheet. The surface
of the mesh sheet is designed to form convexes and concaves which
are larger than the Cry polyhedron 51. Thus the insect control
sheet composed of the first sheet substrate of mesh sheet retains
greater amount of the Cry polyhedron per unit area than the insect
control sheet composed of the first sheet substrate of a flat
plate. In addition, porous structure of mesh sheet facilitates the
manufacture of floatable object where the first sheet substrate is
aerated.
The diagram of the ninth insect control sheet 1i in FIG. 11 shows
the first sheet substrate 10, the pure matrix layer 20, and the
toxin-containing matrix layer 30 being attached to each other
without having a space between them.
FIG. 2 is a sectional view illustrating the second insect control
sheet 1b. The second insect control sheet 1b is different from the
first insect control sheet 1a in the property that the second
insect control sheet 1b includes the first sheet substrate
containing bubbles. Other properties such as the elements and the
materials constituting the layers are the same as that of the first
insect control sheet 1a. The first sheet substrate, which makes the
difference, is explained below.
The second insect control sheet 1b includes the bubble-containing
first sheet substrate 10a. The bubble-containing first sheet
substrate 10a contains a plurality of bubbles 16. Thus the
bubble-containing first sheet substrate 10a has low specific
gravity and decreases the specific gravity of the second insect
control sheet 1b to make the sheet floatable on water.
The bubble-containing first sheet substrate 10a is manufactured in
the processes as exemplified below:
(1) Forming the first material into a sheet, holding the first
material sheet in a pressurized inert atmosphere to make the sheet
contain the inert gas, and foaming the first material sheet by
heating under normal pressure;
(2) Forming the first material into a sheet, simultaneously making
the sheet contain water, and foaming the water-containing sheet by
heating; or
(3) Making a bubble-containing material by adding a known blowing
agent including hydrocarbons such as propane or ethers such as
dimethyl ether to the first material.
FIG. 3 is a sectional view illustrating the third insect control
sheet 1c. The third insect control sheet 1c is different from the
first insect control sheet 1a in the property that the third insect
control sheet includes the bubble-containing second sheet substrate
11 layered on the first sheet substrate 10. Other properties such
as the elements and the materials constituting the layers are the
same as that of the first insect control sheet 1a. The
bubble-containing second sheet substrate, which makes the
difference, is explained below.
The third insect control sheet 1c includes the bubble-containing
second sheet substrate 11 layered on the top side of the first
sheet substrate 10. The bubble-containing second sheet substrate 11
contains a plurality of bubbles 16. The bubble-containing second
sheet substrate 11 has low specific gravity and decreases the
specific gravity of the third insect control sheet 1c to make the
sheet floatable on water.
The third insect control sheet 1c is manufactured by, for example,
forming the pure matrix layer 20 and the toxin-containing matrix
layer 30 on the first sheet substrate 10 and layering or bonding
the bubble-containing second sheet substrate 11 on the top side of
the first sheet substrate 10.
The materials, foaming process, and degradation or dissolution time
of the bubble-containing second sheet substrate 11 are the same as
that of the first sheet substrate 10. The foaming process for the
bubble-containing second sheet substrate 11 is the same as that for
foaming the bubble-containing first sheet substrate 10a.
FIG. 4 is a sectional view illustrating the fourth insect control
sheet 1d. The fourth insect control sheet 1d is different from the
first insect control sheet 1a in the property that the fourth
insect control sheet 1d includes the toxin-containing matrix layer
containing bubbles. Other properties such as the elements and the
materials constituting the layers are the same as that of the first
insect control sheet 1a. The bubble-toxin-containing matrix layer
30a, which makes the difference, is mentioned below.
The bubble-toxin-containing matrix layer 30a, one of the elements
of the fourth insect control sheet 1d, contains a plurality of
bubbles 56 and the Cry polyhedron 51. The bubble-toxin-containing
matrix layer 30a has low specific gravity and decreases the
specific gravity of the fourth insect control sheet 1d to make the
sheet floatable on water.
The bubble-toxin-containing matrix layer 30a is manufactured in the
processes as exemplified below:
(1) Adding bubbles, such as air bubbles, to a mixture of the third
material and the Cry polyhedron being knead, and hardening the
mixture; and
(2) Manufacturing a bubble-containing material by adding a known
blowing agent including hydrocarbons such as propane or ethers such
as dimethyl ether to a mixture of the third material and the Cry
polyhedron.
FIG. 5 is a sectional view illustrating the fifth insect control
sheet 1e.
The fifth insect control sheet 1e is different from the first
insect control sheet 1a in the property that the fifth insect
control sheet 1e includes the first sheet substrate having two
layers between which air cells are contained. Other properties such
as the elements and the materials constituting the layers are the
same as that of the first insect control sheet 1a. The
double-layered first sheet substrate, which makes the difference,
is mentioned below.
The fifth insect control sheet 1e include the first sheet substrate
10 having two layers composed of the top first sheet substrate 10b
and the bottom first sheet substrate 10c. The top first sheet
substrate 10b and the bottom first sheet substrate 10c are
partially separated to form air cells 15. Thus the first sheet
substrate 10 composed of the top first sheet substrate 10b and the
bottom first sheet substrate 10c has low specific gravity to
decrease the specific gravity of the fifth insect control sheet 1e
so as to make the sheet floatable on water.
FIG. 5 shows the bottom sheet substrate 10c, the pure matrix layer
20, and the toxin-containing matrix layer 30 being attached to each
other.
FIG. 6 is a sectional view illustrating the sixth insect control
sheet 1f.
The sixth insect control sheet 1f includes the hydrophobic region
13 made into a pattern on the underside of the first sheet
substrate 10, and also includes the pure matrix layer 20 and the
toxin-containing matrix layer 30 layered on the underside of the
first sheet substrate where the hydrophobic region is not made. The
patterns of the hydrophobic region 13 include, for example,
checkered patterns, latticed patterns and dot patterns. The
relative position of the hydrophobic region and the layers
including the pure matrix layer can be described as an alternate
arrangement.
Substances, especially sheet-shaped substances, coated with a
hydrophobic material is floatable on water. The sixth insect
control sheet 1f has the hydrophobic regions on its underside which
are formed partially and exposed. Thus the sixth insect control
sheet 1f is floatable on water.
The hydrophobic region may be formed by spreading a hydrophobic
material. The hydrophobic region may also be formed by applying a
water-repellent finish on the surface of the first sheet substrate
10. Examples of the hydrophobic material include fluorochemical
water-and-oil repellent agents and particulate hydrophobic oxides
(refer to Reference C-4). Examples of the water-repellent finish
include embossing.
Reference
Reference C-4: JP 4348401
FIG. 7 is a sectional view illustrating the seventh insect control
sheet 1g.
The seventh insect control sheet 1g includes the hydrophobic region
formed on the first sheet substrate 10 in the same manner as that
of the sixth insect control sheet 1f. The hydrophobic region 13 of
the seventh insect control sheet 1g is formed on the top side of
the first sheet substrate. Other properties such as the elements
and the materials constituting the layers are the same as that of
the first insect control sheet 1a.
As shown in FIG. 7, the hydrophobic region 13 of the seventh insect
control sheet 1g is formed on the top side of the first sheet
substrate 10. The hydrophobic region 13 is exposed on the outside
of the seventh insect control sheet 1g to make the sheet floatable
on water.
The hydrophobic region 13 may be formed all over the top side of
the first sheet substrate 10 or on some part of the top side of the
first sheet substrate 10. Making the hydrophobic region all over
the top side is advantageous to easy forming of the hydrophobic
region.
The design may be made on the underside of the first sheet
substrate of any of the insect control sheets of the first to the
ninth. The design includes letters and graphics, and may be made by
printing, drawing, or embossing the surface of the first sheet
substrate. Examples of the design include caution for the
replacement of the insect control sheet, disposal methods for the
first sheet substrate, and notice for proper hygiene.
At the beginning of the use of the insect control sheet, the
underside of the first sheet substrate is covered with the pure
matrix layer and toxin-containing matrix layer which make the
design invisible. At the final term of the use, the pure matrix
layer and toxin-containing matrix layer disappear to make the
design visible and attract the attention of the user.
The design should preferably be printed or drawn with edible inks
for the insect control sheet used in a water tank of daily life
water including drinking water.
The pure matrix layer and/or the toxin-containing matrix layer may
be colored to hide the design more effectively at the beginning of
using the insect control sheet. The layers of the insect control
sheet used in a water tank of daily life water including drinking
water should preferably be colored with food dyes.
FIG. 8 is a sectional view illustrating the insect control
article.
The insect control article 6 includes the pure matrix layer 120
layered on the underside, which contacts with water, of the body
117 floatable on water, and the toxin-containing matrix layer 130
containing the Cry polyhedron is layered on the underside of the
pure matrix layer.
The pure matrix layer 120 is composed of the degradable or
water-soluble second material, and the toxin-containing matrix
layer 130 is composed of the degradable or water-soluble third
material and the Cry polyhedron 51.
The materials and forms of the body 117 are not specifically
restricted, and can be selected from any materials and forms which
make the body floatable on water and capable of sustainably
releasing the Cry polyhedron 51 from the toxin-containing matrix
layer layered on the body 117. Examples of the forms and materials
of the body 117 include wooden bodies of various forms and
boat-shaped or lid-shaped bodies of metals or synthetic resins.
The pure matrix layer is layered on the underside of the body which
contacts with water.
The surface of the body 117 and the pure matrix layer 120 are
bonded by the adhesive layer 60. The materials of the adhesive
layer include fibrin glue, gelatin glue, cyanoacrylates, urethane
prepolymers, hydrogels, cross-linked polysaccharides, natural
adhesive resins such as Japanese lacquer, mixtures of these
materials, and mixtures of these materials and biodegradable
resins. These materials mentioned here have low human health
risks.
The structure of the toxin-containing matrix layer 130 is the same
as that of the toxin-containing matrix layer 30 of the insect
control sheets. The matrix material constituting the
toxin-containing matrix layer 130 are the same as that of the third
material for the insect-control sheets. The structure of the pure
matrix layer 120 is the same as that of the pure matrix layer 20 of
the insect control sheets. The material constituting the pure
matrix layer 120 are the same as that of the second material for
the insect-control sheets.
FIG. 9 is a sectional view illustrating the transfer sheet for
fabricating the insect control article.
The transfer sheet 70 is fabricated by layering the
toxin-containing matrix layer 130, the pure matrix layer 120 and
the adhesive layer 60 in the order on one surface of the
transfer-sheet substrate 71. The materials of the layers are the
same as those mentioned in the description of the insect control
article 6.
Examples of the transfer-sheet substrate 71 include a sheet of
polyvinyl alcohol (PVA). The insect control article 6 can be
fabricated by floating the transfer sheet 70 on water surface and
pressing the body 117 against the transfer sheet to transfer the
layers from the sheet to the body. The PVA dissolves in water to
disappear.
The transfer sheet 70 is capable of forming insect control layers
on the body 117 having a curved surface.
The transfer sheet 70 mentioned by reference to FIG. 9 is a
so-called water transfer sheet. The transfer sheet for fabricating
the insect control article may be a transfer sheet ordinary used
for transfer printing in the air. A film finished with a release
agent may be employed for the substrate of such transfer
sheets.
Examples of materials used for the transfer-sheet substrate include
sheets of resins such as polypropylene resins, polyethylene resins,
polyamide resins, polyester resins, acrylic resins, polyvinyl
chloride resins, polycarbonate resins, polyurethane resins,
polystyrene resins and acetate resins; cellulose sheets such as
glassine paper, coated paper, and cellophane; and sheets of the
composite of these materials.
The transfer sheet 70 may be used to fabricate the insect control
sheets.
The insect control sheets and articles mentioned above may include
the toxin-containing layer and/or the pure matrix layer containing
feeds liked by harmful insects, such as yeast. Such layers attract
harmful insects near the insect control sheets and articles to
improve the effect of insect control.
REFERENCE SIGNS LIST
1a: First insect control sheet 1b: Second insect control sheet 1c:
Third insect control sheet 1d: Fourth insect control sheet 1e:
Fifth insect control sheet 1f: Sixth insect control sheet 1g:
Seventh insect control sheet 1h: Eighth insect control sheet 1i:
Ninth insect control sheet 6: Insect control article 10: First
sheet substrate 10a: Bubble-containing first sheet substrate 10b:
Top first sheet substrate 10c: Bottom first sheet substrate 11:
Bubble-containing second sheet substrate 12: Hydrophobic part 13:
Hydrophobic part 15: Air cell 16: Bubble 20: Pure matrix layer 30:
Toxin-containing matrix layer 30a: Bubble-toxin-containing matrix
layer 51: Cry polyhedron 56: Bubble 60: Adhesive layer 70: Transfer
sheet 71: Transfer-sheet substrate 117: Body 120: Pure matrix layer
130: Toxin-containing matrix layer
* * * * *
References